A×B=0.19×0.19 0.19 ×0.10 0.10 ×0.19 1 (0.19+0.05 ×2)×0.19 =0.0551 2 (0.19+0.05 ×2)× (0.19+0.05 )-0.05 ×0.05× 2 =0.0646 (0.19+0.05 ×2)× (0.1+0.05)-0.05 ×0.05×2 =0.0385 (0.1+0.05 ×2)× (0.19+0.05)-0.05 ×0.05×2 =0.043 3 (0.19+0.05)× (0.19+0.05) -0.05 × 0.05=0.0551 (0.19+0.05) ×(0.1+0.05)- 0.05×0.05 =0.0335 (0.1+0.05) ×(0.19+0.05)- 0.05×0.05 =0.0335 4 (0.19+0.05 ×2)× (0.19+0.05 ×2)-0.05 × 0.05×4 =0.074